This invention relates to pulsed-transmission, echo-ranging sonar systems, and more particularly, to the class of side-scanning sonars that use a synthetic aperture to form search beams. The primary objective of this invention is to allow a hydrophone array of length L to move a distance equal to one complete array length between each transmission rather than only one half the array length as is the case with conventional synthetic aperture sonar (SAS). A further objective is that the projector element need not be physically longer than the distance moved between transmissions, L.
A third objective is to minimize the length of the real hydrophone array as well as the number of elements in the array for any given resolution requirement.
Another objective is to minimize the size of the projector elements.
Still another objective is to make maximum effective use of the limited length of any given towfish upon which the array is mounted.
A further objective of the invention is to allow the towfish velocity to double compared to a conventional SAS.
A further objective is that all this be accomplished so that the resulting beam patterns are of quality substantially identical to those from real (ideal) apertures of similar design requirements.